Lumens vs Lux

You may have come across the terms lumens and lux as you research LED lights. Lets take a look at what these terms mean and what is the difference.

Lumen (lm)

  • Lumen is a unit of luminous flux, or the total amount of visible light emitted by a light source
  • Simplified – lumens measure how much visible light is emitted

Lux (lx)

  • Measures illuminance, or the amount of light on a surface per unit area
  • 1 lux is equal to 1 lumen per square meter
  • For example, a 1,000 lumen bulb that shines on only 1 square metre, the surface will be lit at 1,000 lux. If you move the light away to shine on 4 square metres, the surface will be lit at 250 lux
  • Lux will vary based on the distance from the light source, and the type of reflector used to cast the light
  • Simplified – lux measures how bright your surface will be

 The takeaway, lumens are the amount of light emitted and lux measures the brightness of a surface. Lux will depend on the amount of lumens, light reflector and distance from the light source.

When evaluating your light purchase, always keep in mind the purpose of the light and determine which beam pattern (spot, flood, combo) will be best suited to your situation.